A light-emitting diode (LED) is a semiconductor electronic device capable of emitting light. It owns the advantages of saving power, high efficiency, rapid response time, long lifetime, containing no mercury, and environmental benefits. In recent years, it has been applied to lighting extensively. For general LED packaging, in addition to protecting LED chips, the requirement in light transmittance results in special requests in materials, package methods, and structures. LEDs are developed from early visible-light LEDs all the way to invisible-light LEDs. In particular, ultraviolet (UV) LED products are mainly applied to the light curing market. Compared to traditional light curing, UV LED light curing has better curing efficiency. For example, the intensity (W) and energy (J) of UV LEDs are superior to traditional curing light sources. The UV intensity is stronger. Besides, due to the faster curing and solidification speed by using UV LEDs as the curing light source, the involvement of UV LEDs in the curing market grows up rapidly.
Moreover, UV LEDs can be further applied to antibiosis, preventing dusts, purification, sterilization, and other similar biochemical applications given their superior efficacy. In addition, due to their advantages of small size, long lifetime, and low power consumption, the application fields of UV LEDs have gone beyond the light curing market and to home appliances, such as air purifiers, water purifiers, refrigerators, air conditioners, and dishwashers, and medical apparatuses and the likes. They have gradually become indispensable devices in daily lives.
Nonetheless, instead of plane light sources, current LED package structures are generally point light sources. Considering the indexes of refraction of the materials, it does easily cause that a total reflection is occurred in package structures, the design for plane light sources is a challenge. Besides, UV light has short wavelengths, which means it carries higher energy. For the light field of point light sources, the energy will be more concentrated. Thereby, extra optical components are required for UV LEDs to diffuse UV light for avoiding excessively concentrated energy, which might lead to uncontrollable conditions, such as excessive illumination during light curing.
Accordingly, for solving the above problems, the present invention provides an LED package structure having a plane light source and the method for manufacturing the same. The lateral light emission of the package structure is improved and hence forming a plane light source and making the UV energy distributed more uniformly.